Battery-powered vehicles, such as electric vehicles or hybrid electric vehicles, may contain one or more high-voltage battery packs connected to a DC bus. The high-voltage battery pack may be used as the primary power source of a vehicle to drive various primary loads (e.g., traction motors) and various auxiliary loads (e.g., HVAC, lighting, pumps, etc.). To improve the system reliability and availability, the high-voltage battery pack may be configured as multiple battery strings connected to the DC bus in parallel. However, as the number of the battery strings increase, the system complexity also rises. For example, because of the input capacitance of the loads, initial connection of a battery string to the DC bus may generate a severe inrush current that may damage electrical components of the vehicle. The level of the inrush current may be determined by a difference between the output voltage of the battery string and the voltage of the DC bus. Because the battery strings may have different output voltages and the timing of connecting each battery string to the DC bus may be different, a sophisticated system for connecting unbalanced battery strings to the DC bus is needed to limit the inrush current.
The disclosed system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.